0:00

Okay, let's take a look at this companion case.

0:02

It kind of goes with our platyspondyly case,

0:06

and it goes with our vignette on ankylosing spondylitis.

0:10

And in ankylosing spondylitis,

0:12

we saw how the vertebra were affected at their corners.

0:16

They were depressed at the corners,

0:18

and they were inflamed in the middle, right there,

0:21

so that they almost made a convex upward appearance

0:25

of the vertebra.

0:26

In fact, the vertebra looked a little bit

0:27

conical or oval in shape.

0:30

And then we showed an example of a connective

0:32

tissue abnormality where we had

0:34

basically a planar appearance,

0:37

a platyspondyly or vertebral planar

0:40

appearance of the vertebral body.

0:42

And that's a companion vignette two.

0:44

And now we have the complete opposite of our

0:47

ankylosing spondylitis case where the disc

0:51

end plate complex is bowing outward.

0:54

In fact, these are fish mouthing.

0:56

And we've said in prior vignettes

0:58

that this is a sign of softening.

1:01

So let's talk about bone softening for a minute.

1:05

I mean,

1:05

anything that gives you metabolic disease or a

1:12

subtype of connective tissue disease where the

1:15

bone doesn't form properly. For instance,

1:17

we showed you an example of pseudo rheumatoid

1:20

arthritis in another vignette, and in that case,

1:23

the cartilage didn't form properly,

1:25

but the bone formed properly.

1:27

So the bone did not fish mouth.

1:30

The cartilage is what was collapsing,

1:32

whereas in this case,

1:34

this is a primary bone problem.

1:36

In other words,

1:37

the bone is not forming structurally the right

1:40

way. So the discs, they look great,

1:43

they're huge, they're big, they're bright,

1:45

they're juicy, they're delicious,

1:47

you could eat them, but the vertebra, no,

1:52

not so much.

1:53

So this fish mouthing appearance sends you

1:57

in a completely different direction.

1:59

Now, you can get a lot of help from imaging.

2:01

For instance,

2:02

you see a lot of fish mouthing in certain

2:05

infiltrative diseases. Not all,

2:07

but an example of an infiltrative disease

2:10

would be leukemia, for instance,

2:12

in a child or multiple myeloma where

2:15

you get a lot of collapse.

2:16

So myeloma would be in a different age group.

2:18

But in both of those entities,

2:20

you're never going to see marrow like this.

2:23

You're never going to see marrow that this

2:25

that is so bright and white and smooth.

2:28

So that takes you completely out

2:30

of the diagnosis of leukemia,

2:32

obviously metastases myeloma,

2:36

and it even takes you out of the diagnosis of a

2:39

cause of vertebral plana called Eosinophilic

2:41

Granuloma or Langerhans Cell Histiocytosis.

2:45

So the marrow signal intensity along with

2:48

the shape is extremely valuable.

2:51

The fact that it's a younger patient kind of

2:54

takes you out and it's a man takes you out of

2:57

the diagnosis of conventional osteoporosis even.

3:00

The patient has had a vertebral plasty

3:03

to get some symptomatic relief.

3:05

This happens to be osteogenesis imperfecta.

3:09

I'm showing it as an example

3:11

of somebody who has this fish mouth phenomenon.

3:14

Let's just talk a little bit for a minute about

3:16

patients that have vertebral plana.

3:19

That's kind of a unique differential diagnosis.

3:22

You can remember it with a couple of Mnemonics.

3:24

One is MELT, I for infection, M for metastasis,

3:28

E for Eosinophilic granuloma, L for leukemia,

3:31

lymphoma and T for trauma.

3:33

And then you get into another Mnemonic,

3:35

which I'm sure we all love,

3:37

FETISH,

3:38

which stands for traumatic fractures.

3:42

That should be pretty easy with the history of E.

3:45

Eosinophilic granuloma, T for tumor metastasis,

3:49

especially myeloma and leukemia. Remember,

3:52

myeloma has no nodes.

3:53

Leukemia may or may not have nodes.

3:56

Lymphoma almost always has nodes.

3:59

Dissease may have nodes, but myeloma no nodes.

4:03

You get back into infection and then steroids

4:06

with avascular necrosis at the endplate

4:09

of vertebral bodies, an oft-forgotten one,

4:10

and then multiple hemangiomas

4:13

can give you vertebral Plana,

4:14

but usually not more than a few levels.

4:18

So oi tarta.

4:22

This is a genetic condition.

4:24

It's found on the COL1A 1/2 locus,

4:31

and it's characterized by fractures

4:33

with minimal or absent trauma,

4:35

much like ankylosing spondylitis,

4:37

where they get very severe fractures due to

4:40

the fusions and this sort of very glassy,

4:43

delicate appearance of the bone.

4:45

And they also have variable dentogenesis,

4:48

so they have a lot of dental problems.

4:49

They have hearing loss,

4:51

and those are really critical

4:53

features to the diagnosis.

4:55

The skeletal deformities are important

4:58

because they frequently end up

5:00

being misdiagnosed as child

5:03

abuse or non-accidental trauma.

5:05

So recognizing this in the axial skeleton will

5:10

help avert that very embarrassing situation

5:13

where somebody is inappropriately accused of

5:17

producing multiple fractures due

5:19

to non-accidental trauma.

5:21

So this even lends itself more to an equally

5:25

important reason to make the diagnosis

5:27

not just for the patient themselves,

5:29

but for all the folks around them.

5:31

The fractures, by the way,

5:32

can occur in any bone.

5:34

They're actually more common in the long bones

5:36

than they are in the vertebral bodies.

5:39

And I think that's enough for

5:40

osteogenesis imperfectata.

5:42

It is one of the causes of fish mouthing.

5:45

And we've shown you three configurations of the

5:48

vertebral bodies as well as the marrow signal

5:50

intensity that will lead you in an appropriate

5:53

direction with regard to your differential

5:56

diagnosis. Let's move on, shall we?